Well, you just need good weapons. you can upgrade them in de clear-sky base, where they will get stronger. you can also upgrade your armor. when you got that, you can go to the renegades, and try to beat them. (don't forget to save before you start a battle.) However, you need to find cover nearby the enemy. if you found good cover, you can start the fight. always shoot as high as possible on the heads of the renegades. if you have to reload, hide behind your cover. that's it O, and don't forget to check the (dead) enemy's body after the battle.